1. Field of the Invention
The present invention relates to the field of TFT-LCD (Thin Film Transistor Liquid Crystal Display) techniques, and in particular to a TFT-LCD array substrate's manufacturing method, and a LCD panel and a LCD device using the array substrate.
2. The Related Arts
Following the development of information society, demands for flat-panel display are rapidly growing. TFT-LCD has advantages such as small form factor, low power consumption, zero radiation, etc., and therefore has a leading position in the flat-panel display market. However, due to the intense competition among manufacturers, enhancing display quality, increasing yield, and lowering production cost become key survival factors for manufacturers in the intense competition.
The mainstream manufacturing methods for a TFT-LCD array substrate are the so-called 4Mask and 5Mask techniques. The 5Mask technique involves the applications of a Gate Mask, an Active Mask, an S/D Mask, a Via Hole Mask, and a Pixel Mask. Each of the aforementioned masking process further involves steps of Thin Film Deposition, Etching (including Dry Etch and Wet Etch), and Peeling. Therefore, a complete manufacturing process involves 5 cycles of Thin Film Deposition, Masking, Etching, and Peeling.
Developed from the 5Mask technique, the 4Mask technique uses a Gray Tone Mask, or a Half Tone Mask, or a Single Slit Mask (SSM) to combine the Active Mask and the S/D Mask into a single mask. Then, by adjusting the Etching step, a single masking step can achieve the same effect originally requiring two masking steps of the Active Mask and the S/D Mask.
However, no matter whether the 4Mask technique or the 5Mask technique is used, the minimum gap in an ITO (Indium Tin Oxide) pattern formed using ITO mask is 2.25 um. For a smaller gap, the ITO pattern would suffer the problem of not being able to be broken up by etching at places corresponding to the smaller gaps. The current design and manufacturing technique also cannot reduce the gaps in an ITO pattern any smaller. It is also difficult to enhance the transmittance of a TFT-LCD array substrate by reducing the gaps in the ITO pattern.